1. Routing In Wireless Mesh Networks
A term project by
Dilshad Haleem
Dilshad Haleem CSE534 fall 2006
Dilshad Haleem CST500 fall 2006

2. Routing In Wireless Mesh Networks
Introduction
Architecture
Motivation
Ad Hoc On Demand (AODV)
Research Question
OPNET
Dilshad Haleem CSE534 fall 2006

3. Dilshad Haleem CSE534 fall 2006
Introduction
An IEEE based wireless network
Consists of an interconnection of wireless mesh router
and wireless mesh client with a static backbone.
Two types of mesh client nodes
Type I are equivalent in function as a mesh router (AP)
Type II nodes include wide range of devices, like PDA’s,
laptops or cell phones
Nodes operate as a host and also as a router, forwarding
packets
Reliable , resilient, robust and easily deployed
They are self configuring networks, if a node stop working , a new route is discovered to destination. They are very low cost , very easily deployed especially in areas where there are only one Internet Gateway a mesh of nodes can be created and internet access can be available to many users.
Dilshad Haleem CSE534 fall 2006
Dilshad Haleem CST500 fall 2006

4. Dilshad Haleem CSE534 fall 2006
Architecture
Dilshad Haleem CSE534 fall 2006

5. Dilshad Haleem CSE534 fall 2006
Motivation
Proprietary routing protocols
802.11s task group
Numerous deployments in Arizona
Use of Mobile Ad Hoc Networks’ (MANETs) routing protocols for WMNs (AODV, DSR, OSPF etc)
This lack of standards and the availability of only proprietary routing protocols motivates to design an effecient and scalable routing protocol specifically for WMNs
. Recently researchers have proposed a variety of protocols specifically for WMNs. The IEEE is a set of WLAN standards that define many aspects of wireless networking. One of the aspects is of WMNs which is currently under development by the IEEE s
task group. This task group has issued a call for proposals and received 15 of them in response, form which two have been selected. The standard is expected to be approved by Arizona is the first one to have WMNs deployed in Tempe , chandler and Arizona. . This lack of standards and non proprietary routing protocols motivates the author to perform a simulation study of some of the popular ad hoc routing protocols on WMNs. ad
Dilshad Haleem CSE534 fall 2006
Dilshad Haleem CST500 fall 2006

6. Difference between WMNs and MANETs
Mesh Routers are relatively static
Traffic Model is different
Traffic concentration may be higher in certain paths (hot spots)
Number of users
Dilshad Haleem CSE534 fall 2006

7. Dilshad Haleem CSE534 fall 2006
Ad Hoc On Demand (AODV)
A protocol developed for MANETs
Reactive in operation
Route discovery and maintenance using control packets (RREQ, RREP, RERR and HELLO)
Uses minimum hop count as the performance metric
All these differences between WMNs and MANETs are enough to question the applicability and suitability of ad hoc routing protocols for WMNs. Thus, the routing protocols available for ad hoc wireless network must be modified to suit wireless mesh network. One of the ad hoc protocols that could be considered for WMNs is an Ad Hoc on Demand Distance Vector Protocol (AODV). AODV is a reactive protocol, thus route path is established only when a node has a data packet to send. It reacts relatively fast to the topological changes in a network and only updates host that are affected by the change.
Dilshad Haleem CSE534 fall 2006
Dilshad Haleem CST500 fall 2006

8. Dilshad Haleem CSE534 fall 2006
AODV Operation
Data
Data
RREQ
Source
RERR
RREP
Destination
Dilshad Haleem CSE534 fall 2006

9. Dilshad Haleem CSE534 fall 2006
Research Problem
Simulating AODV for WMNs
Develop pseudo code algorithms to make AODV efficient for WMNs
Dilshad Haleem CSE534 fall 2006

10. Dilshad Haleem CSE534 fall 2006
Proposed Solution
Use of multi-path routing
Use of a different routing metric
Either End-to-End delay or
Expected Transmission Count (ETX)
Dilshad Haleem CSE534 fall 2006

11. Dilshad Haleem CSE534 fall 2006
Simulator: OPNET
A very sophisticated and well established proprietary tool for network simulation
Dilshad Haleem CSE534 fall 2006

12. Dilshad Haleem CSE534 fall 2006
References
[1] Nagesh S. Nandiraju, Deepti S. Nandiraju, Dharma P. Agrawal ,” Multipath Routing in Wireless Mesh Networks” Center for Distributed and Mobile Computing,
Dept. of ECECS, University of Cincinnati - Cincinnati, OH 45221
[2] Charles E. Perkins, Elizabeth M. Royer, “Ad hoc On-Demand Distance Vector Routing.”, Proceedings of the 2nd IEEE Workshop on Mobile Computing Systems and Applications, New Orleans, LA, February 1999, pp
[3] R. Draves, J. Padhye and B. Zill, “Comparison of Routing Metrics for Static Multi-Hop Wireless Networks,” SIGCOMM 2004
[4] R. Draves, J. Padhye and B. Zill, “Routing in Multi-Radio, Multi-Hop Wireless Mesh Networks, ” MOBICOM 2004
[5] Y. Yang, J. Wang and R. Kravets, “Designing Routing Metrics for Mesh Networks,” IEEE Workshop on Wireless Mesh Networks, WiMesh, 2005
[6] K. Ramachandran, M. Buddhikot, G. Chandranmenon, S. Miller, E. Belding-Royer, and K. Almeroth, “On the Design and Implementation of Infrastructure Mesh Networks,” Proc. of IEEE Workshop on Wireless Mesh Networks (WiMesh) , 2005 (invited paper).
Dilshad Haleem CSE534 fall 2006